Sealants are a great way to protect against tooth decay and cavities on back teeth (molars). These are the teeth that are most vulnerable to cavities because they are used in the chewing process, and are the most difficult to reach and clean. The grooves on the teeth are often so narrow that the bristles of a toothbrush can't get in to clean them. Molars first come in at around 5-7 years of age, with a second set coming in between the ages of 11-14. It is best to have a sealant placed when the molars first come in to ensure they are protected early.